Let \(X\)  be of genus \(g=2\) . In this case the theta divisor (REF ) is the image of \(X\)  under (REF ).
M. S. Narasimhan and S. Ramanan, see theorem 2 of [1]}, proved a canonical isomorphism
\(\mathcal {M}^B_X \cong |2\Theta _X|\,\, (\cong ^3).\) 
